On Mon, Feb 20, 2012 at 4:10 AM, Fujii Masao <masao.fu...@gmail.com> wrote: > On Mon, Feb 20, 2012 at 3:08 AM, Robert Haas <robertmh...@gmail.com> wrote: >> On Sun, Feb 19, 2012 at 9:46 AM, Euler Taveira de Oliveira >> <eu...@timbira.com> wrote: >>> On 19-02-2012 02:24, Robert Haas wrote: >>>> I have attached tps scatterplots. The obvious conclusion appears to >>>> be that, with only 16MB of wal_buffers, the buffer "wraps around" with >>>> some regularity >>>> >>> Isn't it useful to print some messages on the log when we have "wrap >>> around"? >>> In this case, we have an idea that wal_buffers needs to be increased. >> >> I was thinking about that. I think that what might be more useful >> than a log message is a counter somewhere in shared memory. Logging >> imposes a lot of overhead, which is exactly what we don't want here, >> and the volume might be quite high on a system that is bumping up >> against this problem. Of course then the question is... how would we >> expose the counter value? > > There is no existing statistics view suitable to include such information. > What about defining pg_stat_xlog or something?
Perhaps pg_stat_perf so we don't need to find a new home every time. Thinking about it, I think renaming pg_stat_bgwriter would make more sense. -- Simon Riggs http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
